With an injection valve with a magnetic actuator the magnetic actuator can be charged up with energy so that initially energy is stored as magnetic energy in the magnetic actuator without the injection valve releasing a flow of fluid. Subsequent to the charging an opening phase can occur in which an injector needle of the injection valve releases a flow of fluid through a metering opening of the injection valve. The opening phase can be followed by a hold phase in which the injector needle is held outside its closed position. These three phases can for example be implemented by a predetermined signal waveform of an actuation signal for the magnetic actuator. The actuation signal with the predetermined signal waveform is generated by an output stage comprising electronic components. The output stage and the injection valve form a metering system.
The magnetic actuation drive operates for example against a nozzle spring which applies a first force to the injector needle in the closing direction and which ensures that the injector needle can suppress the flow of fluid through the metering opening. A second force opposing its closing direction is applied to the injector needle by the magnetic actuator. A third force can be exerted on the injector needle by the fluid in the injection valve. This third force depends on the pressure in injection valve. Thus actuation signals with different signal waveforms can be used for controlling the injection valve, especially the magnetic actuator, depending on the pressure obtaining in the injection valve at the time.
If especially small injection masses are to be metered by means of the injection valve, the magnetic actuator must be supplied with as little energy as possible. Constructional tolerances of the components in the output stage for generating the actuation signal with the predetermined signal waveform can lead to so little energy being transferred to the magnetic actuator that the injector needle opens earlier than desired or does not open at all.